Assembly for use as a clutch or a brake



May 26, 1959 y T L. PAWICK Re. 24,652

' ASSEMBLY FOR usE As A CLUTCH 0R A BRAKE original Filed Feb. 17, 1954 ssheets-Sheet 1 I9 22 3 a I9 25u.I e

ATTORNEY May 26, 1959 ASSEMBLY FOR USE AS A CLUTCH OR A BRAKE FIG. 2

3 Sheets-Sheet 2 44 s '6 4| 395e- 22 IB 4 A r:sv ".I 4o x 5.3 A

u 53\ .,lgalS"r \\V s v 64 l5 f s e@ -N /f' i1- 1" /51/5 l s' @Q M: uw'

INVENTOR.

THOMAS L. FAWICK ATTOR NEY May 26, 1959 T. L. FAwlcK ASSEMBLY FOR usr:As A CLUTCH on A BRAKE 3 Sheets-Sheet 3 original Fned Feb. 1v. 1954 FIGAINVENTOR. THOMAS L.FAw|cK ATTORNEY United States 'Aaten'ti O ASSEMBLYFOR USE AS A `CLUTCH R A BRAKE Thomas L. Fawick, Cleveland, Ohio,asslgnor to Fawick Corporation, a corporation of Michigan Original No.2,857,031, dated October 21, 1958, Serial No. 410,804, February 17,1954. Application for reissue November 17, 1958, Serial No. 774,570

12 Claims. (Cl. 192--85) Matter enclosed in heavy brackets appears inthe original patent but forms no part of this reissue specifica on;matter printed in italics indicates the additions made by reissue.

t This invention relates to torque sustaining clutches or brakes.

Its chief objects are dependability, durability, compactness, ease ofassembly and disassembly, especiallyfory quick and easy substitution ofnew wear-shoes, sim plicity, and economy of construction. Of theaccompanying drawings: f

Fig. 1 is an elevation, with parts sectioned and broken` Fig. 1.

ment surface which is gripped by a set` of circumferentially spacedwear-shoes 19, 19. The mounting for the wear-shoes comprises a clutchelement 13, which can be a fly-wheel, secured, as by bolts 14, 14, uponla shaft 15, which can be a crank-shaft. Secured lto the outer margin ofthe element 13, as by 'bolts 16, 16, is an over-hang clutch ring 17 ofcomplex shape, this ring being formed at circumferentially spacedpositions with* openings extending radially through the ring.l

As shown clearly in Fig. 1, each of these openingsha's a radially outerpart providing a cylinder for a pistonV 18 anda radially inner partproviding a lguidew'ay 17h fora Wear-shoe 19 and seats 17, 17 fora pairof The middle of each spring-20 bearsv against and constantly urgesoutward 'a projection 19;

springs 20, 20.

formed on the adjacent end of the base of the wearshoe, Figs. 1 and 4.Each spring has aninwardly extending apertured end portion, Fig. 4,secured by a screw 21`l toa face of the clutch ring for holding thespring in place when the wear-shoe is moved, axially of 'the' assembly,into or out of its guideway.

Cylinder-heads for all of the cylinders, at the louter ends, areprovided by a cylindrical -ring 22 that surrounds the set of cylindersand is held upon the clutchring 17 by means such as the screw 23, Fig.3. Each cylinder is sealed to the ring 22, as its cylinder-head,` by anO-ring 24 set in an annular groove in the radially outer face of theclutch-ring 17, and each piston has for its packing an O-ring 25 set inan annular groovef formed in the piston, and, if desired, a second suchring, 25, likewise mounted. The invention of course does not exclude,however, the use of a standard metal' piston ring instead of or inaddition to the O-ring.

For lightness each shoe 19 is of webbed constructiom:

'permitting it to move radially of therassemblyy for Reissued May 26,y195.9

"icc

. clutch engagement and disengagement, a retaining plate f ed upon aVscrew stud 29 mounted in the ring 17 and extending through a hole in theretaining plate. Each of the retaining plates is formed with a pair ofpressed-out detents 30, 30 seating in respective recesses formed in thering 17, under the force of the spring 27, to prevent undesired rotationof the retaining plate about the stud 29. Each retaining plate is formedalso with a hole 31 for engagement of the plate by a suitable tool forpulling it suciently to overcome the spring 27 and dislodge the detents30 from their recesses so that the plate can be turned out of the way ofa wear-shoe being removed from or moved into its guideway, axially ofthe assembly.

To facilitate such manipulation of the lwear-shoes each is formed, onits face adjacent the retaining plate, with athreaded hole 32 having inextension thereof a guide hole 33 of smaller diameter, for engagement ofthe shoe by a tool 34, Fig. 2, having portions complemental to the holes32, 33.

The clutch housing, 35, is formed with an access open- ;ing providedwith a removable closure plate 36, Fig. 2,

at a position to which the wear-shoe assemblies can be brought insuccession for removal or insertion of wear shoes. fr v For conductingactuating fluid to and from the pistons 1.: the .clutch element 13 isformed with a radial passage 37 The drum, 10, Fig. 2, is splined upon ashaft 11, and is formed with a frctional-engage-l and a passage 38branching therefrom and leading into an annular groove 39 formed in theface of the member: 13 adjacent the clutch-ring 17. Those two membersare sealed to each other on each side of the annular groove4 39 Iby aradially inward O-ring 40 and a radially outward O-ring 41 set inrespective grooves in the clutch-ring 17.=

At the position of each cylinder the annular groove 39 is incommunication with the cylinder through one:r or more registered pairsof passages such as those shown at v42, 43, Fig. 2, in the members 17and 22, with an shown at the right of Fig. 2.

.by a spring 49.

The first mentioned rotary seal comprises a non-rotating ring 45surrounding the shaft 11 and securedito the bearing housing of theshaft. In a deep annular groove formed in the axially inner face of therin-g 45 are slidably mounted a radially outer slip-seal ring 46 and,spaced radially inward therefrom, a small-diameter slip-seal ring 47.

The outer slip-seal ring 46 is slidably sealed to the" adjacent wiall ofthe recess 'by an O-ring 48 and is backed The inner slip-seal ring isslidably" sealed to the adjacent wall of the recess by an O-ring 50 andis backed by a spring 51'.

The rings 46 and 47 have slip-seal relation toa planesealing face formedupon a uid conducting ring 5,2` which is held against a'shoulder on theshaft 11 by vaI nut 53 and lock-washer 54. n W

The annular space between the slip-seal rings 46, 47 is incommunication, as shown clearly in Fig. 2, withy alternatively usableinlet-outlet pipes 55, 56 for use al-r ternatively'of different clutchactuating uids, such as oil and the nut 53.1

' Suitable passages as shown lead from the annular space between theslip-seal rings 46, 47 to an axial passage 59 in the shaft 11. Thepassage 59 leads to a recess of larger diameter formed in the right-handend face of the shaft 11, in which recess is slidably sealed, an4OL-ring 60, and backed by a spring 61, a `tubular slip-seal member 62having slip-seal relation toy a finiti-conducting disc or plug member 63mounted in a complemental socket formed in the clutch element 13 andhaving communication with the passage37 of the member 13. The" plugmember 63 is sealed to the wall of its socket, on each side of thepassage 37, by an O-ring 64, 64, and 1s retained in its socket by asnap-ring 65. A spacer ring 66 is mounted between the snap-ring 65 andthe outer race of a pilot bearing 67 which journals the end of the shaft11 in the clutch element 13.

At a position within the circle of the adjacent ring 64 the shaft 15 isformed with a recess 68 in its end face and the plug member 63 is formedwith a vent holer69 leading from said recess, so that any leakagepast'the 0- ring can escape through the recess 68, passage 69 and thebearing 67, The building up of back pressure such as would preventproper functioning of the`self-energizing O-ring is thus prevented. Y

Provision for cooling the clutch (or brake.) `drum comprises acooling-liquid supply pipe 70 `from which liquid is discharged through aspout 71 into a chamberdefined "by an annular stamping 72 whichsurrounds the member 52 and is substantially sealed toit and tothemember 45, to which it is secured. At its lowest part' the stamping 72is provided with an outlet spout 73 which. terminates at a position todischarge cooling liquid onto' a low part of the inner face of the rimof the clutch-drum` 10. The radial web of the drum is formed with asetof circumferentially spaced oblique holes 74, 74, Figs. 2 and 3, so thatcooling uid will ow to the other side of t the web. i

The bottom of the clutch housing 35 is provided with a drainage pipe 75,Fig. 3, leading to the intake side ofy a pump, not shown, for returningthe cooling fluid to th inlet pipe 70.

Preferably a suitable oil is used as the cooling uid, so`

that its circulation will provide lubrication for the slipseal faces ofthe rotary seals and for the bearing 67.. As

it circulates independently of the actuating fluid it can be chosen forsuitable cooling as well as lubricating characteristics.

The. operation of the assembly will be manifest from Ithis foregoingdescription.

An important feature of the invention is that each piston 18 and itscylinder provide a brake-actuating or clutch-actuating motoi individualto the associated wear,-

shoe 19. While in normal service each motor appliesl the same amount ofbraking pressure to its shoe as `the* other motors do to theirrespective shoes, all being connected to the sarne source of pressurefluid, yet` each motor can fbe readily serviced or repaired as anindividual motor, and the motors are not all dependentupon-,con-

tinued functioning of a vulnerable annular diaphragm,

as in the case of some devices of the prior art.

I claim: .j

1. An assembly comprising two relatively rotatable structures adaptedfor frictional, torque-sustaining engagement with each other, one `ofsaid structures having a frictional-engagement surface and the other ofsaid structures comprising an lactuating unit for frictional engage.-ment with said surface, said unit comprising awear-shoe structure, rigidmeans lixed in position in relationrtothe axis and crcumferentl'ally ofthe orbit of the `relative rotation of the said surface and integrallydenng apressure-uid cylinder chamber and, lin integral extensionAthereof, a guideway having torque-sustainingk wallsffor guiding [and]said wear-shoe structure in its engagingy and disengaging movementstoward and from saidfrictional-engagement surface, a piston slidablymountedin.l

Vsaid cylinder chamber for impelling said wear-shoe structure in itsengaging movement, the said guideway-defining means integrally definingalso a lateral passage for mounting `and removal of the entire wear-shoestructure wholly by movement thereof in a direction at right-angles tothe direction of its engaging movement, said piston bearingageinstzlbutfbeing unattached to the said wear-shoe structure, thebearing surfaces of said piston and said wearshoe structure beingcontinuous and unbroken, the cylin-` der chamber and piston beingindividual to the single wear-shoe structure, and the entire wear-shoestructurebeing insertable and removable through thesaid lateral passagewithout interference of any part of the means integrally defining thesaid cylinder chamber and the said guideway, with the piston remainingin the cylinder chamber.

[2. `An. assembly as defined in claim l and including a removableguidewaywall for retaining the wear-shoe in its guideway and meanspivotally mounting the removable guideway wall upon the means definingthe. guideway for turning saidwall of the way of a wear-shoe beingmov'ed axially of the assembly into or out of the guideway] '[3. Anassembly as defined in claim l and including a removable guideway wallfor retaining the wear-shoe in its guideway and in which the removableguideway wall is pivotally mounted for turning it out of the way of' awear-shoe being moved axially of the assembly into or out of itsguideway, and including yielding means for urging said wall 'against theguide-way defining `means as a stop for positioning said wall andpreventing its undesired rotation] [4. An assembly as defined in claim 1in which each` wear-shoe |is formed withmean-s engageable 4by a tool forpulling the wear-shoe, axially of the assembly, from the guideway, thesaid pulling means comprising the wall 'of l a' threaded hole in thewear-shoe and in which the wearshoe is formed with a tool-guiding holein extension of but of smaller diameter than the recited threaded hole]`[5. An assembly as defined in claim l in which the re cited meansdefining the guideway is formed at each end of the wear-shoe spacecircurnferentially of the assembly with an axially andlciroumferentially extending springseat shoulder, each wear-shoe isformed at each of its` i ends with a spring-seat projection overlyingand spaced 'from the said spring-seat shoulder, and the recitedyielding. means comprises a spring interposed betweenv each prlnIg-seatshoulder and the adjacent spring-seat projecion.

[6. An assembly as dened in claim 5 in which each of the-recited springsis of the leaf type `and is secured at one of its ends to theguideway-defining means for retention of the spring in place when thewear-shoe is removed] L [7. An assemblyas defined in claim 1 andincluding a fluid-conducting shaft upon which the recited structurehaving the recited frictional-engagement surface is se# cured, a rotaryseal surrounding the axis of said shaft for conducting actuating uidinto said shaft, and a second rotary Seal surrounding the axis of saidshaft for conducting actuating duid through the other one of the frecited structures to the recited cylinder chambers] 8. An assemblycomprising two relatively rotatable,

fluid-conducting structures adapted for frictional, torque` sustainingengagement with each other and a rotary seal for conducting actuatinguid from one to the other of saidy structures, said rotary sealcomprising a fluid-conducting slip-seal plug seated in a recess formedin and surrounding the axis of one of said structures and incommunication in a radial direction with a Huid-conducting passageformed in that structure, and self-energizing sealing means, at eachside of the said passage, axially ofthe assembly, said sealing meanssurrounding the said" plug and sealing` it to the walls of the saidrecess, and

the oneof the said structures that is formed with the said recess beingformed also with a vent passage extend-1 ing from the door of the saidrecess for venting to a region of lower pressure any uid that may leakpast the adjacent one of the said self-energizing sealing means.

9. An assembly comprising two relatively rotatable structures adaptedfor frictional, torque-sustaining engagement with each other, one ofsaid structures having a frictional-engagement surface and the other ofsaid structures comprising unitarily rigid means dening a rigidlyconnected set of circumferentially spaced., radially disposed cylinderchambers, pistons slidably mounted in the said chambers respectively,and a ring formed separately from said means but constitutingcylinder-head means common to said chambers, the said unitarily rigidmeans and the said ring being formed with a single pair of matingcylindrical faces, and said ring providing closures for all of the saidcylinder chambers and the said ring being axially slidable from saidunitarily rigid means.

10. An rassembly as defined in claim 9 and including, for each cylinderchamber, a self energizing sealing ring sealing the chamber wall to thesaid ring.

11. An assembly comprising two relatively rotatable structures adaptedfor frictional, torque-sustaining engagement with each other, one ofsaid structures .having a frictional-engagement surface and the other ofsaid structures comprising an actuating unit for frictional engagementwith said surface, said unit comprising a wearshoe structure, rigidmeans fixed in position in relation to the axis and circumferentially ofthe orbit of the relative rotation of the said surface and defining botha pressure-fluid cylinder chamber and, in extension thereof, a guidewayhaving torque-sustaining walls for guiding said wear-shoe structure inits engaging and disengaging movements toward and from saidfrictional-engagement surface, a piston slidably mounted in saidcylinder chamber for impelling said wear-shoe structure in its engagingmovement, the said guideway-defining means defining also a lateralpassage for mounting and removal of the entire wear-shoe structurewholly by movement thereof in a direction transverse to the xdirectionof its engaging movement, said piston bearing against but beingunattached to the said wear-shoe structure, the bearing surfaces of saidpiston and said wear-shoe structure being relatively slidable into andout of overlapped relation to each other in such movement, the cylinderchamber and piston being individual to the single wear-shoe structure,and the entire wear-shoe structure being insertable and removablethrough the said lateral passage without interference of any part of themeans defining the said cylinder chamber and the said guideway, with thepiston remaining in the cylinder chamber.

12. An assembly comprising two relatively rotatable structures adaptedfor frictional, torque-sustaining engagement with each other, one ofsaid structures having a frictional-engagement surface and the other ofsaid structures comprising an actuating unit for frictional engagementwith said surface, said unit comprising a wear-shoe structure, rigidmeans fixed in position in relation to the axis and circumferentially ofthe orbit of the relative rotation of the said surface and defining aguideway having torque-sustaining walls for guiding said wear-shoestructure in its engaging and disengaging movements tward and from saidfrictional engagement surface, means for impelling said wear-shoestructure in said guideway in its engaging movement, the saidguideway-defining means defining also a lateral passage for mounting andremoval of the entire wear-shoe structure wholly by movement thereof ina direction transverse to the direction of its engaging movement, saidimpelling means bearing against but being unattached to the saidwearshoe structure, the bearing surfaces of said impelling means andsaid wear-shoe structure being relatively slidable into and out ofoverlapped relation to each other in such movement, the guideway and theimpelling means being individual to the single wear-shoe structure, andthe entire wear-shoe structure being insertable and removable throughthe said lateral passage without interference of any part of the meansdefining the said guideway, with the said impelling means remaining inalignment with the said guideway.

I3. An assembly as defined in claim 12 and including a removableguideway wall for retaining the wear-shoe in its guideway and meanspivotally mounting the removable guideway wall upon the means definingthe guideway for turning said wall out of the way of a wear-shoe beingmoved into or out of its guideway.

14. An assembly as defined in claim 12 and including a removableguideway wall for retaining the wear-shoe in its guideway and in whichthe removable guideway wall is pivotally mounted for turning it out ofthe way of a wear-shoe being moved into or out of its guideway, andincluding yielding means for urging said wall against theguideway-defining means as a stop, for positioning said wall andpreventing its undesired rotation.

15. An assembly as dejned in claim 12 in which each wear-shoe is formedwith means engageable by a tool for pulling the wear-shoe from theguideway, the said pulling means comprising the wall of a threaded holein the wear-shoe, and in which the wear-shoe is formed with atool-guiding hole in extension of but of smaller diameter than therecited threaded hole.

16. An assembly as defined in claim 12 in which the recited meansdefining the guideway is formed at opposite sides with a pair ofspring-seat shoulders and each wear-shoe is formed at opposite sideswith a pair of spring-seat projections respectively overlying and spacedfrom the said spring-seat shoulders respectively, the assembly includinga spring interposed between each springseat shoulder and the adjacentspring-seat projection.

17. An assembly as defined in claim 16 in which each of the recitedsprings is of the leaf type and is secured at one of its ends to theguideway-defining means for retention of the spring in place when thewear-shoe is removed.

18. An assembly as defined in claim 11 and including a fluid-conductingshaft upon which the recited structure having the recitedfrictional-engagement surface is secured, a rotary seal surrounding theaxis of said shaft for conducting actuating fluid into said shaft, and aSecond rotary seal surrounding the axis of said shaft for conductingactuating fluid through the other one of the recited structures to therecited cylinder chamber.

References Cited in the iile of this patent or the original patentUNITED STATES PATENTS 881,510 Warren et al Mar. 10, 1908 899,953Chadwick Sept. 29, 1908 1,047,713 Smith Dec. 17, 1912 2,028,152 GrayIan. 21, 1936 2,060,826 Roberts Nov. 17, 1936 2,229,922 Heinze Jan. 28,1941 2,304,030 Schmitter Dec. 1, 1942 2,324,979 Hatch July 20, 19432,498,123 Hobbs 1 Feb. 2l, 1950 2,588,985 Kutz Mar. 11, 1952 2,710,087Picard June 7, 1955 2,720,866 Maki Oct. 18, 1955 2,823,777 Banker Feb.18, 1958 FOREIGN PATENTS 636,240 France Ian. 7, 1928 831,344 GermanyFeb. 11, 1952 892,261 Germany Oct. 5, 1953

